The audio filter referenced in § 95.2779 must satisfy the requirements in this section.
- (a) The audio filter must be between the modulation limiter and the modulated stage of the transmitter.
- (b) At any frequency (f in kHz) between 3 and 15 kHz, the filter must have an attenuation of at least 40 log (f/3) dB more than the attenuation at 1 kHz. Above 15 kHz, it must have an attenuation of at least 28 dB more than the attenuation at 1 kHz.